Systems and method for a coolant chamber

ABSTRACT

A debubbler system includes a hollow enclosure that includes an inlet and an outlet directing the flow of coolant fluid into and out from the hollow enclosure, respectively. The debubbler system further includes a check valve to exhaust gaseous bubbles in the coolant fluid out of the hollow enclosure to reduce the gaseous bubbles in the coolant fluid. The debubbler system also includes a vent tube fluidly coupled to the check valve, such that the vent tube is positioned opposite a weighted member that is fixed relative to a central axel that rotates about a rotation axis. The debubbler system may be part of a cooling system for cooling electronics systems, such as light-emitting diode (LED) lighting systems.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/965,693, entitled “Debubbler Systems andMethods for Cooling Devices,” filed Jan. 24, 2020, which is herebyincorporated by reference in its entirety for all purposes.

BACKGROUND

The present disclosure relates generally to a coolant chamber for acooling apparatus. In particular, the present disclosure relates tosystems and methods for reducing gas bubbles, managing fluid thermalexpansion, and venting and pressure compensation in cooling systems forlight emitting diode (LED) lighting instruments or other lightinginstruments.

This section is intended to introduce the reader to various aspects ofart that may be related to various aspects of the present techniques,which are described and/or claimed below. This discussion is believed tobe helpful in providing the reader with background information tofacilitate a better understanding of the various aspects of the presentdisclosure. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

Generally, LED lighting instruments may provide lighting for a varietyof applications. In some applications, high intensity lighting from LEDlighting instruments may be enhance lighting and visibility in certainareas. For example, LED lighting instruments may provide high intensitylighting for motion picture and television sets and studios. To providesuch high intensity lighting (e.g., lighting consuming 500 W-1500 W oftotal power), an arrangement of LEDs within the lighting instruments maybe relatively dense and numerous. As the density of LEDs in a givenspace increase, an amount of heat produced by the LEDs and a temperatureof the LEDs may generally increase. Typical Wall Plug Efficiency (“WPE”)of blue LEDs used to make white light may be about 50% such that about50% of the energy will be converted into photons and the other 50% willbe lost as heat. There may be an additional loss when the light isconverted from blue light to white by the phosphors. In these cases,about half of the electrical power provided to LEDs is converted intoheat. As such, it should be appreciated that efficient cooling systemsfor LED systems may enhance performance, longevity, and efficiency ofthe LED systems.

Conventional cooling techniques for lighting systems may notsufficiently cool such high intensity LED lighting instruments.Additionally, Chip Scale Packaging (“CSP”) technology and Chip on Board(“COB”) arrays provide the ability to directly attach LED die to aprinted circuit board (“PCB”) without a package. Typical LED die may beabout 1 millimeter (mm) in size (e.g., a length of the die) or less. TheLED die are packaged separately, which makes them easier to handle inmanufacturing and increases the available area for dissipating heat(e.g., 3 mm×3 mm is a common package for example). In COB and/or CSPtechnology, an array of LED dies may be attached directly to ahigh-resolution PCB which may increase the power density. LED arrayswith power densities of 80 watts per square inch and higher are producedtoday with these CSP and COB technologies with higher power densitiesconstantly being developed. LEDs may typically be maintained at ajunction temperature of less than 125 degrees Celsius or they will bedamaged. Due to the heat restrictions, the packing density of LEDs insystem designs may be effectively limited by heat. However, traditionalair-cooling techniques, such as heat sinks, may not sufficiently coolthe LED lighting instruments. Even adding fans to increase airflow overmetal heat sinks provides limited heat dissipation.

Furthermore, cooling techniques employing cooling fluid may operate insuboptimal manners. For example, as cooling fluid facilitates heatdissipation of the LED lighting instrument, the cooling fluid may besubject to different temperatures, which may decrease and/or increasethe pressure of the cooling fluid in constant volumes. The fluctuationin pressure may create bubbles in coolant fluid flow paths, therebyaffecting the efficiency of the cooling technique. Accordingly, there isa need to improve the lighting instrument cooling by reducing bubbles inthe coolant fluid flow paths, the implementation of which may bedifficult to develop and coordinate in various systems generating hightemperatures.

BRIEF DESCRIPTION

Although the following description describes cooling systems used in anLED assembly, the cooling systems may be deployed in other systems, suchas electronic systems. Debubbler systems and methods disclosed hereinmay reduce bubbles in coolant flow paths associated with light coolingsystems of the LED assembly. The light cooling systems include a coolantfluid configured to flow over the LED assembly along a coolant flow pathto cool LEDs emitting light and to remove heat produced by the LEDs. Apump of the cooling system may circulate the coolant fluid along thecoolant flow path between the LED assembly, a heat exchanger thatremoves the heat from the coolant fluid, and a debubbler system. Adebubbler system may include a hollow enclosure that includes an inletand an outlet to receive the coolant fluid via the coolant fluid flowpath. The debubbler system further includes a check valve to exhaust airbubbles in the coolant fluid out of the hollow enclosure to reduce airbubbles in the coolant fluid. The check valve may be fluidly coupled toa vent tube, such that an opening of the vent tube is above the coolantfluid. The debubbler system may be part of a cooling system for coolingelectronics systems, such as LED lighting systems.

DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings.

FIG. 1 is a perspective view of an embodiment of a lighting assemblyhaving a light emitting diode (LED) assembly and a cooling system, inaccordance with one or more current embodiments;

FIG. 2 is a schematic diagram of an embodiment of the cooling system ofFIG. 1 configured to immersively and actively cool the LED assembly ofFIG. 1, in accordance with one or more current embodiments;

FIG. 3 is a cross-sectional view of the lighting assembly of FIG. 1having the cooling system and the LED assembly, in accordance with oneor more current embodiments;

FIG. 4 is a perspective cross-sectional view of the lighting assembly ofFIG. 1 having the cooling system and the LED assembly, in accordancewith one or more current embodiments;

FIG. 5 is a perspective view of the LED assembly of FIG. 1, inaccordance with one or more current embodiments;

FIG. 6A is a rear perspective view of the lighting assembly of FIG. 1having the cooling system and the LED assembly, in accordance with oneor more current embodiments;

FIG. 6B is a rear perspective view of another embodiment of a lightingassembly having the cooling system of FIG. 1, in accordance with one ormore current embodiments;

FIG. 7 is a perspective view of another embodiment of the cooling systemand the LED assembly of FIG. 1 including a transparent enclosure, inaccordance with one or more current embodiments;

FIG. 8 is a perspective cross-sectional view of the LED assembly and thetransparent enclosure of FIG. 7, in accordance with one or more currentembodiments;

FIG. 9 is a bottom perspective view of the LED assembly and thetransparent enclosure of FIG. 7, in accordance with one or more currentembodiments;

FIG. 10 is a partially exploded view of the LED assembly and thetransparent enclosure of FIG. 7, in accordance with one or more currentembodiments;

FIG. 11 is a side view of the cooling system of FIG. 7 and a side viewof an embodiment of a lighting assembly, in accordance with one or morecurrent embodiments;

FIG. 12 includes side views of the cooling system of FIG. 7, inaccordance with one or more current embodiments;

FIG. 13 includes perspective views of the cooling system of FIG. 7coupled to light directing assemblies, in accordance with one or morecurrent embodiments;

FIG. 14 is a perspective cross-sectional view of another embodiment of alighting assembly having the LED assembly and the cooling system of FIG.1, in accordance with one or more current embodiments;

FIG. 15 is a perspective view of the lighting assembly of FIG. 14, inaccordance with one or more current embodiments;

FIG. 16 is a flow diagram of an embodiment of a method for controllingthe cooling system of FIGS. 1-15, in accordance with one or more currentembodiments;

FIG. 17 is a cross-sectional view of the debubbler system of FIG. 1, inaccordance with one or more current embodiments;

FIG. 18A is a cross-sectional view of the debubbler system of FIG. 1 ina first orientation having a weighted member at the bottom of thedebubbler system of FIG. 1, in accordance with one or more currentembodiments;

FIG. 18B is a cross-sectional view of the debubbler system of FIG. 1 ina second orientation having an inlet oriented opposite a direction of agravity vector, in accordance with one or more current embodiments;

FIG. 18C is a cross-sectional view of the debubbler system of FIG. 1 ina third orientation, in which the outlet is positioned opposite agravity vector, in accordance with one or more current embodiments;

FIG. 19 is a flow diagram of a first arrangement of the cooling systemof FIG. 1, including the debubbler system of FIG. 1, in accordance withone or more current embodiments;

FIG. 20 is a flow diagram of a second arrangement of the cooling systemof FIG. 1, including the debubbler system of FIG. 1, in accordance withone or more current embodiments;

FIG. 21 is a flow diagram of a third arrangement of the cooling systemof FIG. 1, including the debubbler system of FIG. 1, in accordance withone or more current embodiments;

FIG. 22 is a schematic diagram of cooling system of FIG. 1, includingthe debubbler system of FIG. 1, in accordance with one or more currentembodiments;

FIG. 23 is a perspective view of an inside of an enclosure of thedebubbler system of FIG. 1, in accordance with one or more currentembodiments;

FIG. 24 is a cross-section view of the debubbler system of FIG. 1,including a fluid level sensor, in accordance with one or more currentembodiments;

FIG. 25 is a cross-section view of the debubbler system of FIG. 1,including the fluid level sensor of FIG. 24, in accordance with one ormore current embodiments;

FIG. 26 is a cross-section view of the debubbler system of FIG. 1,including the fluid level sensor of FIG. 24, in accordance with one ormore current embodiments;

FIG. 27A is a schematic diagram of the lighting assembly of FIG. 1oriented in an upward position, in accordance with one or more currentembodiments;

FIG. 27B is a schematic diagram of the lighting assembly of FIG. 1oriented in a horizontal position, in accordance with one or morecurrent embodiments; and

FIG. 27C is a schematic diagram of the lighting assembly of FIG. 1oriented in a downward position, in accordance with one or more currentembodiments.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will bedescribed below. These described embodiments are only examples of thepresently disclosed techniques. Additionally, in an effort to provide aconcise description of these embodiments, all features of an actualimplementation may not be described in the specification. It should beappreciated that in the development of any such actual implementation,as in any engineering or design project, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one implementation toanother. Moreover, it should be appreciated that such a developmenteffort might be complex and time consuming, but may nevertheless be aroutine undertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments of the presentdisclosure, the articles “a,” “an,” and “the” are intended to mean thatthere are one or more of the elements. The terms “comprising,”“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements.Additionally, it should be understood that references to “oneembodiment,” “an embodiment,” or “some embodiments” of the presentdisclosure are not intended to be interpreted as excluding the existenceof additional embodiments that also incorporate the recited features.

While the following discussion is generally provided in the context of acooling system for an LED assembly for a lighting system, it should beunderstood that the embodiments disclosed herein are not limited to suchlighting contexts. Indeed, the systems, methods, and concepts disclosedherein may be implemented in a wide variety of applications. Theprovision of examples in the present disclosure is to facilitateexplanation of the disclosed techniques by providing instances ofreal-world implementations and applications. It should be understoodthat the embodiments disclosed herein may be useful in manyapplications, such as electronics (e.g., mobile devices, processors,memory devices, and so forth), food processing systems, transportationsystems, and/or other industrial, commercial, and/or electronic systemsfor which the reduction of heat may improve cooling and deviceperformance and longevity.

As discussed above, conventional cooling techniques for electronicsystems, such as lighting systems, may not sufficiently cool. Forexample, existing cooling techniques for high intensity LED lightinginstruments may suffer from certain drawbacks. As an example, coolingtechniques employing cooling fluid may face some challenges because ascooling fluid is used to facilitate heat dissipation of the LED lightinginstrument, the cooling fluid may be subject to different temperatures,which may decrease and/or increase the pressure of the cooling fluid inconstant volumes. When the pressure increases inside the conduits orcomponents that receive the cooling fluid, the pressure exerted on thewalls of the conduits or components due to the expansion of air andcoolant fluid may damage the walls of the conduits and components.

While manufacturing the walls of the conduits or the components out offlexible and expandable materials may reduce the impact of this increasein pressure, such manufacturing practice may not eliminate the airbubbles that may result from the increase in pressure. Indeed, thefluctuation in pressure may create bubbles in coolant fluid flow paths,thereby affecting the efficiency of the cooling technique. For example,a pump (e.g., high speed centrifugal pump) driving cooling fluid throughthe coolant fluid flow paths may operate in an undesired manner (e.g.,stop pumping coolant fluid) if the impeller cavity is filled with air(e.g., from the air bubbles). As another example, if a larger air bubblecollects in the LED lighting instrument, the LED may not receiveadequate cooling and thermally fail. Accordingly, existing systems maybenefit from improvements to cooling of the LED lighting instrument byreducing bubbles in the coolant fluid flow paths, the implementation ofwhich may be difficult to develop and coordinate in various systemsgenerating high temperatures.

The presently disclosed embodiments included a debubbler system thatincludes a check valve that may reduce the internal pressure of thedebubbler system and thereby reduce the air bubbles that may be presentwithin the debubbler system. The debubbler system may be positionedalong a cooling circuit defining the flow of fluid, for example, used tocool an electronic device. The cooling circuit may define the flow offluid between an electronic system, the debubbler system, a heatexchanger, a pump, and/or any other suitable devices. In this manner, asthe pump controls the flow of fluid, the debubbler system may remove theair bubbles in the fluid to improve the overall cooling efficiency ofthe electronic device. The debubbler system may reduce pressure from theoverall cooling circuit by allowing pressure built up within the coolingcircuit to vent out of the debubbler system, as discussed in detailbelow. Removing pressure from the cooling circuit may be difficultbecause the cooling circuit may be a closed system. In this manner, thedebubbler system may prevent changes in volume (e.g., expansion andcontraction) resultant from changes in pressure by allowing for the ventof air bubbles and pressure, as discussed in detail below.

As used herein, “debubbler system” may refer to a device for removingbubbles from a fluid system, in accordance with embodiments of thepresent disclosure. For example, debubbler system may refer to atri-functional coolant chamber that may allow for fluid thermalexpansion, may capture bubbles and air in system, and vent and/orcompensate for pressure changes. The debubbler system may benon-pressurized or pressurized (e.g., to about 6 pounds per square inch(psi)). In the case of the debubbler system being pressurized, thedebubbler system may be compressible and expandable, for example, due tothe enclosure of the debubbler system being of a compressible material.As used herein, “fluid” or “coolant fluid” may refer to a substance usedfor cooling purposes that has no fixed shape and yields to externalpressures. As used herein, “bubble” or “air bubble” may refer to aglobule of one substance (e.g., a gas) in another (e.g., liquid), suchas an air bubble in the coolant fluid. While the embodiments below arediscussed in the context of “air bubbles,” it should be understood thatthe present embodiments may be applied to bubbles of any gaseoussubstance.

Furthermore, the embodiments discussed herein include a discussion ofvarious flow paths (e.g., fluid connections or coolant circuits). Theflow paths (e.g., fluid connections or coolant circuits) may includemultiple segments fluidly coupling two components of the cooling system.Furthermore, the segments are each configured to direct coolant fluid.In certain embodiments, the segments are configured to direct coolantfluid with no intervening components between the illustrated components.For example, each illustrated segment of each illustrated coolant fluidflow path may include a first end and a second end configured to form adirect fluid connection (e.g., via an annular conduit) between twocomponents. However, in certain embodiments, intervening components maybe present between the two illustrated components.

During transportation of the debubbler system (e.g., after manufacturingthe debubbler system), preventing air from entering the main coolingsystem may help preserve functionality of the cooling system bypreventing the accumulation of air bubbles. Air bubbles in the coolingsystem may be undesirable because when an air bubble sits over alighting element, the coolant does not flow over the lighting element,which could lead to overheating or cooling inefficiencies. Despitemessages (for a desired orientation for the debubbler system) on thepackaging used to transport the debubbler system or on the debubblersystem, transporting companies may fail to follow the message, resultingin harm to the lighting system. To improve the transportability andversatility of the lighting system by allowing for a number oforientations or positions during transportation and use, presentembodiments for the debubbler system include one or more designs forpreventing air from exiting the debubbler system and entering thelighting assembly when the debubbler system is in any number oforientations, for example, during use or transportation.

Lighting System

Turning now to the drawings, FIG. 1 is a perspective view of anembodiment of a lighting assembly 70 having a cooling system 80 and theLED assembly 82, in accordance with one or more current embodiments. Thelighting assembly 70 includes a reflector 85 (e.g., a parabolicreflector) configured to reflect light emitted by the LED assembly 82.For example, the light emitted by the LED assembly 82 may pass throughthe fluid disposed between the LED assembly 82 and the enclosure 88,through the enclosure 88, and may be reflected by the reflector 84outwardly. The reflector 84 is coupled to a chassis 86 (e.g., a housing)of the lighting assembly 70. In certain embodiments, the LED assembly82, the enclosure 88, and/or other portions of the cooling system 80 maybe coupled to the chassis 86. For example, as described in greaterdetail below, a heat exchanger and/or pump of the cooling system 80 maybe coupled to the chassis 86. To facilitate illustration, FIG. 1includes a coordinate system fixed to the lighting assembly and defininga longitudinal axis 90, a lateral axis 92, and a vertical axis 94.

Cooling System

FIG. 2 is an exemplary schematic diagram of a cooling system 80 of FIG.1 configured to actively cool the LED assembly 82 of FIG. 2, inaccordance with one or more current embodiments. The cooling system 80includes an enclosure 88 configured to at least partially enclose and/orhouse the LED assembly 82 and a heat exchanger 106 fluidly coupled tothe enclosure 88. The cooling system 80 also includes a pump 108configured to circulate fluid (e.g., coolant, mineral oil, water, ahydrocarbon fluid, a silicon fluid, any suitable cooling fluid, or acombination thereof) along a cooling circuit 110 through the heatexchanger 106, through the enclosure 88, through and/or over the LEDassembly 82, through a debubbler system 112, and back to the pump 108.In certain embodiments, the cooling system 80 may include the LEDassembly 82 or a portion thereof.

The LED assembly 82 may be any assembly including one or more LEDs. Forexample, to provide lighting for applications such as television andtheater sets, film sets, tradeshows, and any one of the range ofpermanent, semi-permanent, and temporary settings, the LED assembly 82may include multiple LEDs configured to emit light. While emittinglight, the LEDs may produce heat and a temperature of a surrounding area(e.g., an area adjacent to the LED assembly 82 and/or within/adjacent tothe enclosure 88) may generally increase.

During operation, the cooling system 80 is configured to absorb the heatgenerated by the LED assembly 82 and to transfer the heat to ambientair. For example, as the pump 108 circulates the fluid through theenclosure 88 and/or through the LED assembly 82, the fluid may absorbthe heat generated by the LED assembly 82. The heat exchanger 106 mayinclude a radiator and/or fan(s) configured to actively draw ambient airtoward/across the heat exchanger 106 to cool the fluid traveling throughthe heat exchanger 106 and along the cooling circuit 110, as describedbelow. In certain embodiments, the heat exchanger 106 may include asecond fluid (e.g., in addition to or in place of the ambient air)configured to exchange heat with the fluid flowing along the coolingcircuit 110.

The pump 108 may be a variable speed pump configured to circulate thefluid through the cooling circuit 110. In certain embodiments, a housingof the pump 108 may include a flexible diaphragm configured to expandand/or contract based on a volume of the fluid flowing along the coolingcircuit 110. For example, as the fluid absorbs heat at and from the LEDassembly 82, the fluid may expand (e.g., thermal expansion). As thefluid flows from the LED assembly 82 and the enclosure 88, the flexiblediaphragm of the pump 108 may expand to allow the increased volume offluid to pass through the pump without affecting the flowrate of thefluid through the pump 108 and along the cooling circuit 110. In someembodiments, the flexible diaphragm of the pump 108 may be a servicepanel configured to allow access to internal portions of the pump 108.As described in greater detail below, in certain embodiments, theflexible diaphragm may be located elsewhere along the cooling circuit110 (e.g., in addition to or in place of be located at the pump 108) tofacilitate thermal expansion of the fluid in the cooling circuit 110.

The debubbler system 112 may include a hollow enclosure having an inletthat receives fluid along the cooling circuit 110 to remove air bubblesthat build in the fluid as the fluid flows along the cooling circuit110. The debubbler system 112 may include a check valve 114 thatrestricts the flow of fluid to one direction. In this case, the checkvalve may allow fluid (e.g., air) out of the debubbler system 112, suchthat the check valve prevents fluid (e.g., air) from entering thedebubbler system. The debubbler system 112 may also include an outletthat allows the fluid to exit the debubbler system to flow to anothercomponent along the cooling circuit 110. The debubbler system may alsoinclude a fluid level sensor 115 to monitor the fluid level inside thedebubbler system 112. A detailed discussion of the debubbler system 112is provided below with respect to FIGS. 17-27.

The LED assembly 82 is configured to emit light, which may pass throughthe fluid circulating between the LED assembly 82 and the enclosure 88and through the enclosure 88. As such, the LED assembly 82 is configuredto provide lighting for the various applications described herein (e.g.,motion picture and television lighting and/or other applications thatmay benefit from high intensity lighting) while being cooled by thecooling system 80. The LEDs of the LED assembly 82 may includevaried/multiple configurations. For example, the LED assembly 82 mayinclude chip scale packaging (CSP) arrays (e.g., bi-color CSP arrays).CSP technology may benefit from high density of LED chips in a specifiedarea (e.g., per square inch/centimeter), and CSP technology may utilizedifferent colors of individual LEDs. For example, CSP technology mayinclude a five color configuration (e.g., warm white, cool white, red,green, and blue), a four color configuration (e.g., white, red, green,and blue), a three color configuration (e.g., red, green, and blue), abi-color white configuration (e.g., warm white and cool white), a singlewhite configuration, and/or a single color configuration.

In some embodiments, the LED assembly 82 may include single color chipon board (“COB”) arrays. The COB arrays may include a relatively largenumber of LEDs bonded to a single substrate and a layer of phosphorplaced over the entire array. An advantage of COB technology is veryhigh LED density per specified area (e.g., per square inch/centimeter).Additionally or alternatively, the LED assembly 82 may include discreteLEDs.

The cooling system 80 includes a controller 120 configured to controland/or receive signals from the LED assembly 82, the heat exchanger 106,the pump 108, the debubbler system 112 (e.g., fluid level sensor 115),or a combination thereof. For example, the controller 120 may controlsome or all LEDs of the LED assembly 82 to cause the LEDs to emit light.Additionally or alternatively, the controller 120 may control operationof the heat exchanger 106 to cause the heat exchanger 106 to exchangemore or less heat between the fluid and the ambient air. For example,the controller 120 may control fans of the heat exchanger 106 to controlan air flow rate through/over the heat exchanger 106. In certainembodiments, the fans of the heat exchanger 106 may be controlled viapulse width modulated (PWM) power. The fans may be controlled based onthe temperature at the LED assembly 82. In some embodiments, to reduce anoise output of the fans of the heat exchanger 106, the controller 120may operate the fans when cooling of the fluid by other means (e.g., viathe radiator without active airflow) is insufficient.

As illustrated, the cooling system 80 may include a sensor 121 disposedat the LED assembly 82 and configured to output a signal (e.g., an inputsignal into the controller 120) indicative of the temperature at the LEDassembly 82 and/or a temperature of the fluid adjacent to the LEDassembly 82. The sensor 121 may be any suitable temperature/thermalsensor, such as a thermocouple. In certain embodiments, the coolingsystem 80 may include other thermal sensor(s) disposed within the fluidand configured to output a signal indicative of a temperature of thefluid (e.g., within the enclosure 88) and/or disposed at the enclosure88 and configured to output a signal indicative of a temperature at theenclosure 88.

Further, the controller 120 may control operation of the pump 108 tocause the pump 108 to circulate the fluid along the cooling circuit 110at particular flowrates. For example, based on the temperature at theLED assembly 82 and/or at the enclosure 88 (e.g., based on the signalindicative of the temperature at the LED assembly 82 received from thesensor 121), the controller 120 may be configured to output a signal(e.g., an output signal) to the pump 108 indicative of instructions toadjust the flowrate of the fluid flowing through the cooling circuit110. Furthermore, the fluid level sensor 115 may be communicativelycoupled to the controller 120. In certain embodiments, the controller120 may be configured to output a signal (e.g., an output signal) to thepump 108 indicative of instructions to adjust the flowrate of the fluidflowing through the cooling circuit 110 based on a fluid level insidethe debubbler system 112 (e.g., as determined by the fluid level sensor115). For example, if the fluid level is below (or above) a fluid levelthreshold value as determined by the fluid level sensor 115, thecontroller 120 may be output a signal (e.g., an output signal) to thepump 108 indicative of instructions to increase (or decrease) theflowrate of the fluid flowing through the cooling circuit 110 toincrease (or decrease) volume of fluid within the debubbler system 112.

As illustrated, the controller 120 includes a processor 122 and a memory124. The processor 122 (e.g., a microprocessor) may be used to executesoftware, such as software stored in the memory 124 to control thecooling system 80 (e.g., for controller operation of the pump 108 tocontrol the flowrate of fluid through the cooling circuit 110).Moreover, the processor 122 may include multiple microprocessors, one ormore “general-purpose” microprocessors, one or more special-purposemicroprocessors, and/or one or more application-specific integratedcircuits (ASICS), or some combination thereof. For example, theprocessor 122 may include one or more reduced instruction set (RISC) orcomplex instruction set (CISC) processors.

The memory device 124 may include a volatile memory, such asrandom-access memory (RAM), and/or a nonvolatile memory, such asread-only memory (ROM). The memory device 124 may store a variety ofinformation and may be used for various purposes. For example, thememory device 124 may store processor-executable instructions (e.g.,firmware or software) for the processor 122 to execute, such asinstructions for controlling the cooling system 80. In certainembodiments, the controller 120 may also include one or more storagedevices and/or other suitable components. The storage device(s) (e.g.,nonvolatile storage) may include ROM, flash memory, a hard drive, or anyother suitable optical, magnetic, or solid-state storage medium, or acombination thereof. The storage device(s) may store data (e.g.,measured temperatures at the LED assembly 82) in relational ornon-relational data structures, instructions (e.g., software or firmwarefor controlling the cooling system 80), and any other suitable data. Theprocessor 122 and/or the memory device 124, and/or an additionalprocessor and/or memory device, may be located in any suitable portionof the system. For example, a memory device for storing instructions(e.g., software or firmware for controlling portions of the coolingsystem 80) may be located in or associated with the cooling system 80.

Additionally, the controller 120 includes a user interface 126configured to inform an operator of the temperature at the LED assembly82 and/or of the flowrate of the fluid through the cooling circuit 110.For example, the user interface 126 may include a display and/or otheruser interaction devices (e.g., buttons) configured to enable operatorinteractions. It is understood that FIG. 2 is intended to provide anexemplary schematic diagram of the cooling system 80, and the componentsof the cooling system 80 (such as the pump 108, the heat exchanger 106,the debubbler system 112, and the LED assembly 82) are not limited bythe quantity and coupling as shown in FIG. 2, and instead, may berepositioned at various points along the cooling circuit 110.

FIG. 3 is a cross-sectional view of the lighting assembly 70 of FIG. 2having the cooling system 80, in accordance with one or more currentembodiments. As illustrated, the cooling system 80 includes theenclosure 88, the LED assembly 82 disposed in the enclosure 88, the heatexchanger 106 configured to exchange heat with the fluid, and the pump108 configured to drive circulation of the fluid. Additionally and asillustrated, the cooling system 80 includes an inlet pipe 140 coupled tothe pump 108 and to a fluid inlet 142 of the enclosure 88. Further, thecooling system 80 includes an outlet pipe 144 coupled to an outlet 146of the enclosure 88 and to the heat exchanger 106. In certainembodiments, the inlet pipe 140 and/or the outlet pipe 144 may extendinto the LED assembly 82 and/or into the enclosure 88.

As illustrated, the fluid inlet 142 may be disposed generally along acenterline of the enclosure 88 and the LED assembly 82. The pump 108 maybe configured to drive the fluid from the inlet pipe 140, into the fluidinlet 142, generally along the centerline of the LED assembly 82 and theenclosure 88, into and along a gap between the LED assembly 82 and theenclosure (e.g., a gap where the fluid absorbs heat generated by the LEDassembly 82), out of the fluid outlet 146, and into the outlet pipe 144(e.g., along the cooling circuit 110). After absorbing heat at the LEDassembly 82, the fluid may circulate through the heat exchanger 106 andreturn to the pump 108. At the heat exchanger 106, the fluid rejects theheat absorbed at the LED assembly 82. For example, the heat exchanger106 includes a radiator 150 and fans 152 configured to draw air (e.g.,ambient air) across the radiator 150. The air drawn across the radiator150 may absorb heat from the fluid flowing through the radiator 150(e.g., heat transferred from the fluid to the radiator 150), therebycooling the fluid for subsequent circulation along the cooling circuit110 and back through the LED assembly 82 and the enclosure 88.

In certain embodiments, the heat exchanger 106 may not expel all theheat absorbed by the fluid at the LED assembly 82, such that the fluidretains at least some of the heat absorbed at the LED assembly 82. Assuch, a temperature of the fluid along the cooling circuit 110 (e.g., anaverage temperature) may increase, thereby increasing a volume of thefluid. The cooling system 80 may include a flexible membrane 154 at thepump 108 configured to expand due to heating of the fluid and tocontract due to cooling of the fluid (e.g., to accommodate volumetricchanges of the fluid along the cooling circuit 110). In certainembodiments, the flexible membrane 154 may be included elsewhere withinthe cooling system 80.

The cooling system 80 may include a valve 156 fluidly coupled to thecooling circuit 110. The valve 156 may be configured to bleed air and/orfluid from the cooling circuit 110, such as when fluid is added to thecooling circuit 110 (e.g., the valve 156 may be a bleed valve).Additionally or alternatively, fluid may be added to the cooling circuit110 via the valve 156 (e.g., the valve 156 may include a fill valve). Incertain embodiments, the cooling system 80 may include multiple valves156 with a first valve 156 being a bleed valve and a second valve 156being a fill valve.

As described above, the controller 120 may be configured to control theLED assembly 82, the heat exchanger 106, the pump 108, the debubblersystem 112, or a combination thereof. For example, the controller 120may control some or all LEDs of the LED assembly 82 to cause the LEDs toemit light. Additionally, the controller 120 may control a rotation rateof the fans 152 and/or a flow rate of the fluid along the coolingcircuit 110. For example, based on feedback received from the sensor 121at the LED assembly 82 (e.g., the temperature at the LED assembly 82),the controller 120 may control the rotation rate of the fans 152 and/orthe flow rate of the fluid. More specifically, in response thetemperature at the LED assembly 82 being greater than a targettemperature and a difference between the temperature at the LED assembly82 and/or the target temperature exceeding a threshold value, thecontroller may increase the rotation rate of the fans 152 and/or mayincrease the flow rate of the fluid. In response the temperature at theLED assembly 82 being less than the target temperature and thedifference between the temperature at the LED assembly 82 and/or thetarget temperature exceeding a threshold value, the controller maydecrease the rotation rate of the fans 152 and/or may decrease the flowrate of the fluid.

FIG. 4 is a perspective cross-sectional view of the lighting assembly 70of FIG. 2 having the cooling system 80, in accordance with one or morecurrent embodiments. As illustrated, the fluid of the cooling system 80is configured to flow from the inlet pipe 140, through the fluid inlet142, and through an inner annular passage 160 formed within the LEDassembly 82 (e.g., in a direction 162). As such, the fluid enters theLED assembly 82 as a chilled fluid. The inner annular passage 160 may becoupled to the fluid inlet 142 and to an end 164 of the LED assembly 82.From the inner annular passage 160, the fluid may circulate through anend passage 166 formed between the end 164 of the LED assembly 82 and anend 168 of the enclosure 88, as indicated by arrows 170. From the endpassage 166, the fluid circulates into an outer annular passage 172formed between the LED assembly 82 and the enclosure 88, as indicated byarrow 174. As the fluid flows through the outer annular passage 172, thefluid absorbs heat generated by the LED assembly 82. From the outerannular passage 172, the fluid exits the enclosure 88 through the fluidoutlet 146 and flows into the outlet pipe 144. As such, the fluid exitsthe enclosure 88 as a heated fluid. After passing through the heatexchanger 106 and the pump 108 of the cooling system 80, the fluidcirculates back through the LED assembly 82 and the enclosure 88 tocontinue cooling the LED assembly 82.

The lighting assembly 70 is a side emission configuration of thelighting assembly, such that the lighting assembly 70 is configured toemit light radially outwardly (e.g., from sides of the lighting assembly70) and through the fluid and the enclosure 88. As described in greaterdetail below in reference to FIGS. 14 and 15, the cooling system 80 mayinclude a front emission configuration of the lighting assembly, such asin place of or in addition to the side emission configuration of FIGS.2-5.

FIG. 5 is a perspective view of the LED assembly 82 of FIG. 2, inaccordance with one or more current embodiments. As illustrated, the LEDassembly 82 includes a tower 180 and LED arrays 182 mounted to the tower180. As illustrated, the tower 180 is a hexagonal structure formed bypanels 184 (e.g., six panels 184) with nine LED arrays 182 mounted oneach panel 184. In certain embodiments, the tower may include more orfewer panels 184 (e.g., three panels 184, four panels 184, eight panels184, etc.) and/or each panel 184 may include more or fewer LED arrays182 (e.g., one LED array 182, two LED arrays 182, five LED arrays 182,twenty LED arrays 182, etc.). In some embodiments, the tower 180 may beshaped differently in other embodiments and/or may be omitted. Forexample, the LED arrays 182 may be mounted directly to the enclosure 88in some embodiments. In certain embodiments, the LED assembly 82 mayinclude other LED configurations in addition to or in place of the LEDarrays 182.

The LED arrays 182 of the LED assembly 82 are configured to emit lightoutwardly through the fluid flowing between the LED assembly 82 and theenclosure 88 (e.g., through the outer annular passage 172 formed betweenthe LED assembly 82 and the enclosure 88) and through the enclosure 88.The fluid may be transparent or semi-transparent such that the fluid isconfigured to allow the light to pass through the fluid toward theenclosure 88. For example, the fluid may be a dielectric and/orelectrically insulating fluid having a refractive index of between 1.4and 1.6. In some embodiments, the enclosure 88 enclosing the fluid maybe acrylic, polycarbonate, glass (e.g., borosilicate glass), or anothermaterial having a refractive index between about 1.44-1.5. In certainembodiments, the LEDs of the LED arrays 182 may include silicone (e.g.,a silicone layer) through which light emitted by the LEDs passes. Thesilicone may have a refractive index of about 1.38-1.6. As such, a typeof fluid (e.g., the fluids having the refractive indices within theranges recited above) may facilitate light passage from the LEDs,through the fluid, and toward the enclosure 88. Additionally, therefractive index of the layer of the LED (e.g., the silicone), thefluid, and/or the enclosure 88 may generally be matched (e.g., within adifference threshold). In some embodiments, the fluid and/or theenclosure 88 may behave as lens configured to optically shape lightprovided by the LED assembly 82. For example, the fluid and/or theenclosure 88 having the specific refractive indices described above mayallow the fluid and/or the enclosure to shape the light to enhanceillumination of the LED assembly 82.

Additionally or alternatively, the fluid may include a mineral oilhaving a relatively long shelf life (e.g., about twenty-five years) or afluid having properties similar to mineral oil. The fluids may benon-corrosive such that the fluids facilitate pumping along the coolingcircuit 110 by the pump 108 and compatible with plastics and othersystem materials. Further, such fluids may generally have a relativelylow viscosity, which may allow directly cooling the electronics of theLED assembly 82 (e.g., the LED arrays 182, wiring coupled to the LEDarrays 182 and to printed circuit boards (“PCB's”), and other electroniccomponents of the LED assembly 82) without affecting theperformance/functionality of the electronics. In certain embodiments,the type of the fluid included in the cooling circuit 110 may depend onan amount of LED arrays 182 and/or an amount of LEDs generally includedin the LED assembly 82, a structure/geometry of the LED assembly 82, adensity of LEDs of the LED assembly 82, an amount of heat generated bythe LED assembly 82, or a combination thereof. During operation, the LEDarrays 182 of the LED assembly 82 may have a power density of between 20W-300 W per square inch, between 50 W-250 W per square inch, and othersuitable power densities. In an aspect, each LED array 182 may have asurface area of 4 square inches or less. Due to the cooling systemsmentioned herein, the LED arrays 182 may be operated at theaforementioned power densities for longer than 30 seconds, 1 minute, 1hour, and 80 hours. In some embodiments, the LED assembly 82 may have atotal power of 400 W-5000 W.

In some embodiments, the refractive index of the fluid disposed betweenthe LED arrays 182 and the enclosure 88 may cause light to more easilyleave the LED arrays 182 compared to an embodiment in which the LEDarrays 182 are exposed to air. This may result in a color shift of thelight emitted from the LED arrays 182. The controller 120 may controlthe LED arrays 182 (e.g., the colors and/or color temperatures of theLED arrays 182) based on the potential color shift of the emitted light.

The enclosure 88 may include clear, transparent, and/or semi-transparentmaterials such that the light emitted by the LED assembly 82 may passthrough the enclosure 88 (e.g., after passing through the fluid disposedwithin and/or flowing through the outer annular passage 172) andoutwardly from the enclosure 88. For example, the enclosure 88 may beformed of a clear plastic and/or glass (e.g., borosilicate glass). Incertain embodiments, the enclosure 88 may include poly(methylmethacrylate) (“PMMA”) and/or other acrylics.

As illustrated, the LED assembly 82 includes printed circuit boards(“PCBs”) 190 coupled to a base PCB 192, the LED arrays 182, and the end164 (e.g., end plate) of the LED assembly 82. For example, each PCB 190extends generally along a respective panel 184 and is coupled (e.g.,physically and electrically coupled via connectors 193) to the LEDarrays 182 coupled to the respective panel 184. Each connector 193 iscoupled to a respective LED array 182 at connections 194. In certainembodiments, each LED array 182 may be configured to snap/click intoplace on the panel 184. For example, each panel 184 may include featuresconfigured to receive the LED arrays 182 via a snap or click mechanismto facilitate assembly of the LED assembly 82.

FIG. 6A is a rear perspective view of the lighting assembly 70 of FIG. 2having the cooling system 80, in accordance with one or more currentembodiments. As generally described above, the cooling system 80includes the inlet pipe 140 configured to flow fluid (e.g., chilledfluid) into the LED assembly 82 and the enclosure 88 and the outlet pipe144 configured to receive fluid (e.g., heated fluid) from the LEDassembly 82 and the enclosure 88. The fluid circulates from the outletpipe 144, through the radiator 150 of the heat exchanger 106, throughthe pump 108, and back to the inlet pipe 140. As illustrated, thecooling system includes four fans 152 configured to draw air across theradiator 150 to cool the fluid passing through the radiator 150. Incertain embodiments, the cooling system may include more or fewer fans152 (e.g., one fan 152, two fans 152, three fans 152, five fans 152, tenfans 152, etc.). The fans 152 are positioned above the radiator 150,such that the heat transferred from the fluid passing through theradiator 150 moves generally upwardly toward/through the fans 152.Additionally, the heat exchanger 106 and the pump 108 are mounted to thechassis 86 of the lighting assembly 70.

FIG. 6B is a rear perspective view of an embodiment of a lightingassembly 187 having the cooling system 80 of FIG. 1, in accordance withone or more current embodiments. The lighting assembly 187 includes theinlet pipe 140 configured to flow fluid (e.g., chilled fluid) into theLED assembly 82 and the enclosure 88 and the outlet pipe 144 configuredto receive fluid (e.g., heated fluid) from the LED assembly 82 and theenclosure 88. The fluid circulates from the outlet pipe 144 to theradiator 150, through the radiator 150, to an intermediate pipe 189,through an expansion chamber 188 coupled to the intermediate pipe 189,and back to the inlet pipe 140 via the pump 108. The expansion chamber188 is configured to expand due to heating of the fluid and to contractdue to cooling of the fluid (e.g., to accommodate volumetric changes ofthe fluid along the cooling circuit 110). In certain embodiments, theexpansion chamber 188 may be included elsewhere along the coolingcircuit 110, such as along the inlet pipe 140 and/or along the outletpipe 144.

As illustrated, the lighting assembly 187 includes a first bracket 191coupled to the radiator 150 and the expansion chamber 188 and a secondbracket 195 coupled to the radiator 150 and the pump 108. The radiator150 and the expansion chamber 188 are mounted to the first bracket 191,and the first bracket 191 is mounted to the chassis 86, such that thefirst bracket 191 is configured to support a weight of the expansionchamber 188 and/or at least a portion of a weight of the radiator 150(e.g., to transfer forces associated with the weight(s) to the chassis86). Additionally, the radiator 150 and the pump 108 are mounted to thesecond bracket 195, and the second bracket 195 is mounted to the chassis86, such that the second bracket 195 is configured to support a weightof the pump 108 and/or at least a portion of the weight of the radiator150 (e.g., to transfer forces associated with the weight(s) to thechassis 86).

FIG. 7 is a perspective view of an LED assembly 196 and an enclosure 198that may be included the cooling system 80 of FIG. 1, in accordance withone or more current embodiments. As illustrated, the LED assembly 196 isdisposed within the enclosure 198. The LED assembly 196 includes a fluidinlet 200 configured to receive the fluid flowing along the coolingcircuit 110 (e.g., as indicated by arrow 202) and a fluid outlet 204configured to flow the fluid from the enclosure and the LED assembly 196to the cooling circuit 110 (e.g., as indicated by arrow 206) (althoughthe fluid direction may be reversed such that the fluid enters throughthe fluid outlet 204, for example, and exits through the fluid inlet200). Additionally, the enclosure 198 includes a base 208 and a cylinder210 extending from the base 208. In certain embodiments, the LEDassembly 196 and/or the enclosure 198 of the cooling system 80 may beincluded in the lighting assembly of FIGS. 2-6.

The LED assembly 196 includes a tower 220 and the LED arrays 182 mountedto the tower 220. As illustrated, the tower 220 is a hexagonal structurewith nine LED arrays 182 mounted on each of the six sides of thehexagonal structure. In certain embodiments, the tower 220 may includemore or fewer sides (e.g., three sides, four sides, eight sides, etc.)and/or each side may include more or fewer LED arrays 182 (e.g., one LEDarray 182, two LED arrays 182, five LED arrays 182, twenty LED arrays182, etc.). In some embodiments, the tower 220 may be shaped differentlyin other embodiments and/or may be omitted. For example, the LED arrays182 may be mounted directly to the enclosure 198 in some embodiments. Incertain embodiments, the LED assembly 196 may include other LEDconfigurations in addition to or in place of the LED arrays 182.

The LED arrays 182 of the LED assembly 196 are configured to emit lightoutwardly through the fluid flowing between the LED assembly 196 and theenclosure 198 (e.g., through an outer annular passage 224 of the coolingsystem 80) and through the enclosure 198. In some embodiments, theenclosure 198 enclosing the fluid may be acrylic, polycarbonate, glass(e.g., borosilicate glass), or another material having a refractiveindex between about 1.44-1.5. Additionally, the refractive index of thelayer of the LED (e.g., the silicone), the fluid, and/or the enclosure198 may generally be matched (e.g., within a difference threshold).

The enclosure 198 may include clear, transparent, and/orsemi-transparent materials such that the light emitted by the LEDassembly 196 may pass through the enclosure 198 (e.g., after passingthrough the fluid disposed within and/or flowing through the outerannular passage 224) and outwardly from the enclosure 198. For example,the enclosure 198 may be formed of a clear plastic and/or glass (e.g.,borosilicate glass). In certain embodiments, the enclosure 198 mayinclude poly(methyl methacrylate) (“PMMA”) and/or other acrylics.

The cooling system 80 is configured to flow the fluid into the fluidinlet 200, through the outer annular passage 224 between the LEDassembly 196 and the enclosure 198, and toward an end 230 of the tower220. The end 230 is disposed generally opposite of the base 208. Thetower 220 includes an inner annular passage 232 extending from the end230 to the base 208. As illustrated, the inner annular passage 232 isfluidly coupled to the outer annular passage 224 at the end 230 of thetower 220. The cooling system 80 is configured to flow the fluid fromthe outer annular passage 224 and into the inner annular passage 232 viathe end 230. The inner annular passage 232 is fluidly coupled to thefluid outlet 204 such that the fluid may pass through the tower 220, viathe inner annular passage 232, and out of the tower 220 and theenclosure 198 at the fluid outlet 204.

As the fluid passes over and through the LED assembly 196 (e.g., overthe LED arrays 182 and through the tower 220), the fluid is configuredto absorb heat generated by operation of the LED arrays 182. Forexample, because the fluid is configured to absorb heat generated by theLED arrays 182 while flowing through both the outer annular passage 224and the inner annular passage 232, the cooling system 80 is configuredto significantly increase an amount of heat that may be absorbedcompared to embodiments of cooling systems that extract heat from aninterior or exterior of a light source. Additionally, because the fluidis generally transparent and/or semi-transparent (e.g., the fluid has arefractive index generally between 1.4-1.5), the fluid may haveminimal/no effects on the light emitted from the LED assembly 196 andthrough the fluid. As such, the fluid may actively cool the LED assembly196 during operation of the LED assembly 196 with little to no effect ona quality of light emitted from the LED assembly 196.

The LED assembly 196 is a side emission configuration of a lightingassembly, such that the LED assembly 196 is configured to emit lightradially outwardly (e.g., from sides of the LED assembly 196) andthrough the fluid and the enclosure 198. As described in greater detailbelow in reference to FIGS. 14 and 15, the cooling system 80 may alsoinclude a front emission configuration of the lighting assembly, such asin place of or in addition to the side emission configuration of FIGS.7-10.

FIG. 8 is a perspective cross-sectional view of the LED assembly 196 andthe enclosure 198 of FIG. 7, in accordance with one or more currentembodiments. As described above, the enclosure 198 is configured toreceive the fluid from the pump 108 through the fluid inlet 200. Thefluid is then configured to contact the tower 220 and a base 300 of theLED assembly 196 coupled to the tower 220. The tower 220 and the base300 are configured to direct the fluid upwardly along the outer annularpassage 224. The fluid is then configured to flow through the end 230and into the inner annular passage 232. As illustrated, the innerannular passage 232 is formed between and by the tower 220 and PCBs 302of the LED assembly 196. The fluid is configured to flow downwardlywithin the inner annular passage 232 toward a base PCB 304 electricallycoupled to the PCBs 302. After passing over the PCBs 302 and/or the basePCB 304, the fluid is configured to exit the tower 220 and the enclosure198 at the fluid outlet 204. As mentioned with respect to FIG. 7, thefluid direction may be reversed such that the fluid may be configured toflow in through the fluid outlet 204, up through the inner annularpassage 232, through the end 230, and down the outer annular passage224, and out the fluid inlet 200.

The PCBs 302 may be electrically coupled to the LED arrays 182 such thatthe PCBs 302 may provide power and/or communication with the LED arrays182. For example, the LED assembly 196 may include wiring extendingoutwardly between the PCBs 302 and the LED arrays 182. As such, thefluid may flow over the PCBs 302 and the wiring extending between thePCBs 302 and the LED arrays 182 to cool and absorb heat from the tower220 (e.g., heat generated by the LED arrays 182 that is transferredto/absorbed by the tower 220), from the PCBs 302, and/or from thewiring. Additionally, the fluid may flow over the base PCB 304 and mayabsorb heat from the base PCB 304. For example, the base PCB 304includes a wet side 306 configured to contact the fluid and a dry sidegenerally opposite the wet side 306 that is configured to remain dry(e.g., to not contact the fluid). As generally described above, thefluid may be dielectric and/or electrically insulating such that thefluid may have minimal/no electrical effects on the LED arrays 182, thePCBs 302, the base PCB 304, and the wiring of the LED assembly 196.

FIG. 9 is a bottom perspective view of the LED assembly 196 and theenclosure 198 of FIG. 7, in accordance with one or more currentembodiments. As illustrated, the base PCB 304 includes a dry side 400configured to remain generally dry (e.g., to not contact the fluidduring operation of the cooling system 80). The LED assembly 196includes a gasket 402 configured to form a seal between the enclosure198 and the LED assembly 196 (e.g., between the base 208 of theenclosure 198 and the base PCB 304 of the LED assembly 196). As such,the LED assembly 196 may be remain dry at the dry side 400 of the basePCB 304, and the cooling system 80 may be configured to flow the fluidthrough the enclosure 198 and the tower 220 without leaking fluid.

FIG. 10 is a partially exploded view of the LED assembly 196 and theenclosure 198 of FIG. 7, in accordance with one or more currentembodiments. The LED assembly 196 is configured to insert into and to beremoved from the enclosure 198 as generally indicated by arrow 500. Forexample, to replace portions of the LED assembly 196 (e.g., the LEDarrays 182, the PCBs 302, the base PCB 304, wiring, etc.), the LEDassembly 196 and the enclosure 198 may be disassembled by removing theLED assembly 196 from the enclosure 198 along an axis generally parallelto arrow 500. Additionally, while the LED assembly 196 and the enclosure198 are disposed in the illustrated positions (e.g., with the LEDassembly 196 and the enclosure 198 extending downwardly), the LEDassembly 196 may be removed from the enclosure 198 with a minimal lossand/or splashing of the fluid using threaded enclosures, a gasket, alatch, and/or other securing mechanisms. To assemble/reassemble the LEDassembly 196 into the enclosure 198, the LED assembly 196 may beinserted into the enclosure 198 along the axis generally parallel to thearrow 500. Thus, the configuration and coupling of the LED assembly 196and the enclosure 198 described herein may facilitate quick and easymaintenance of the LED assembly 196.

FIG. 11 is a side view of the cooling system 80 of FIG. 7 and a sideview of a lighting assembly 600, in accordance with one or more currentembodiments. As illustrated, the base 208 of the enclosure 198 iscoupled to a heat exchanger 601. After absorbing heat from and at theLED assembly 196, the fluid is configured to flow into and through theheat exchanger 601. The heat exchanger 601 includes a radiator 602configured to exchange heat from the fluid to ambient air adjacent tothe heat exchanger 601. The heat exchanger 601 may include the radiator602 on each of four sides of the heat exchanger 601 (e.g., fourradiators 602). In certain embodiments, the heat exchanger 601 mayinclude more of fewer sides with each side having the radiator 602. Theradiator 602 includes fins 604 configured to transfer heat from thefluid (e.g., to absorb heat from the fluid) to the ambient air. In someembodiments, the heat exchanger 601 may include other shapes configuredto cool the fluid (e.g., a sphere, a cylinder, etc.).

The LED arrays 182 of the LED assembly 196 extend outwardly from thebase 208 of the enclosure 198 a distance 610. In certain embodiments,the distance 610 may be between about three inches and about nineinches. In some embodiments, the distance 610 may be about five andone-half inches. Additionally, the cooling system 80 extends a generallyvertical distance 612 and a generally horizontal distance 614. Incertain embodiments, the generally vertical distance 612 may betweenabout ten inches and about twenty inches, and/or the generallyhorizontal distance 614 may be between about seven inches and aboutseventeen inches. In some embodiments, the generally vertical distance612 may be fourteen inches, and/or the generally horizontal distance 614may be twelve inches.

The lighting assembly 600 is a prior art lighting assembly having alighting area 620 configured to emit light. A back portion of thelighting area 620 may be a heat sink configured to absorb/transfer heatfrom the lighting area 620. As illustrated, the cooling system 80 isgenerally smaller and more compact than the lighting area 620 and theheat sink of the lighting assembly 600. Additionally, as generallydescribed above, the cooling system 80 is configured to providesufficient cooling for the LED assembly 196 as the LED assembly 196operates at 1500 W. The lighting assembly 600 may be configured toprovide cooling for lights of the lighting area 620 operating at 400 W.As such, the cooling system 80 may be more versatile than the lightingassembly 600, and prior art lighting assemblies generally, by providinga more compact design configured to operate at significantly higherpowers. In certain embodiments, the LED assembly 82 and/or the enclosure88 of the cooling system 80 may be coupled to the heat exchanger 601,such that the heat exchanger 601 is configured to exchange heat with thefluid circulating through the LED assembly 82 and the enclosure 88.

FIG. 12 includes side views of the cooling system 80 of FIG. 7, inaccordance with one or more current embodiments. The cooling system 80includes a cover 700 configured to fit over/onto the enclosure 198. Thecover 700 includes materials configured to convert a color correlatedtemperature (“CCT”) of light emitted by the LED assembly 196. Forexample, the cover 700 may include and/or be formed of phosphor and maybe configured to convert a cool white CCT of about 5600K to a warmerwhite CCT of about 4300K, about 3200K, and other CCT's. In certainembodiments, the cover 700 may be injection molded plastic, silicone,coated glass, or a combination thereof. In certain embodiments, thecover 700 may fit over/onto the enclosure 88, such that the cover 700converts a CCT of light emitted by the LED assembly 82 through theenclosure 88.

The cover 700 is configured to slide onto and off of the enclosure 198,as generally noted by arrow 702. For example, the cover 700 may beeasily field changeable such that an operator may slide the cover 700onto and off of the enclosure 198. Additionally, light produced by alow-cost, single-color version of the LED assembly 196 may easily beconverted to any CCT with the addition of the cover 700, which may be ofrelatively low cost. Further, the cover 700 may be significantly morepower efficient compared to traditional embodiments, because the cover700 is not a filter removing a portion of light emitted by the LEDassembly 196. Instead, the cover 700 is configured to convert light to adesired color and CCT.

In certain embodiments, the LED assembly 196 may be configured to emit ablue light, cool white light (e.g., 5000K or higher), or other colors.The cover 700 may adapted for any suitable color and/or white such thatlight emitted from a single-color version of the LED assembly 196 (e.g.,a blue light LED assembly 196 or a cool white light LED assembly 196)may be converted into any CCT and/or any color with no change to the LEDassembly 196 or other electronics of the cooling system 80.

As illustrated, the cover 700 is configured to contact the enclosure 198while the cover 700 is disposed on the enclosure 198. The contactbetween enclosure 198 and the cover 700 may allow the enclosure 198 totransfer heat to the cover 700. The fluid flowing within the enclosure198 may be configured to cool both enclosure 198 and the cover 700(e.g., the fluid may absorb heat from the enclosure 198 to facilitatecooling of the cover 700).

FIG. 13 includes perspective views of the cooling system 80 of FIG. 7coupled to light directing assemblies 800, 802, and 804 configured todirect light emitted by the LED assembly 82 of the cooling system 80, inaccordance with one or more current embodiments. For example, the lightdirecting assembly 800 is a high bay assembly configured to be disposedin building setting and to direct light emitted by the LED assembly 82downwardly. The light directly assembly 802 is a space light directingassembly configured to be disposed in a studio to provide environmentlighting. Additionally, the light directly assembly 804 is an umbrellaassembly configured to be disposed in a studio and to generally focuslight emitted by the LED assembly 82.

FIG. 14 is a perspective cross-sectional view of another embodiment of alighting assembly 820 having an LED assembly 822 and the cooling system80 of FIG. 1, in accordance with one or more current embodiments. Thelighting assembly 820 is a front emission configuration of a lightingassembly that may be included in the cooling system 80, such that thelighting assembly 820 is configured to emit light outwardly through afront portion of the lighting assembly 820, as indicated by arrow 823,rather than through side of a lighting assembly (e.g., as in lightingassembly embodiments of FIGS. 2-13). Accordingly, the cooling system 80may include a lighting assembly having a side emission configuration, afront emission configuration, and/or others.

The lighting assembly 820 includes a chassis 824 configured to receiveand flow the fluid to cool the LED assembly 822. As illustrated, the LEDassembly 822 is disposed within and mounted to the chassis 824.Additionally, the lighting assembly 820 includes a cover 826 coupled tothe chassis 824. The cover 826 is configured to at least partiallyenclose the lighting assembly 820, such that the cover 826 directs thefluid through the lighting assembly 820 and over the LED assembly 822.Additionally, the cover 826 may include clear, transparent, and/orsemi-transparent materials such that the light emitted by the LEDassembly 822 may pass through the cover 826 (e.g., after passing throughthe fluid) and outwardly from the cover 826. For example, the cover 826may be formed of a clear plastic and/or glass (e.g., borosilicateglass). In certain embodiments, the cover 826 may include poly(methylmethacrylate) (“PMMA”) and/or other acrylics and/or other materialsdescribed herein.

The chassis 824 includes a fluid inlet 830 configured to receive thefluid flowing along the cooling circuit 110 (e.g., as indicated by arrow832) and a fluid outlet 834 configured to flow the fluid from thechassis 824 to the cooling circuit 110 (e.g., as indicated by arrow 836)(although the fluid direction may be reversed such that the fluid entersthrough the fluid outlet 834, for example, and exits through the fluidinlet 830). Additionally, the chassis 824 includes a base 840 and acylinder 842 extending from the base 840. The base 840 includes thefluid inlet 830 and the fluid outlet 834. In certain embodiments, theLED assembly 822 and/or the chassis 824 may be included in the lightingassembly and/or LED assembly of FIGS. 2-13.

The LED assembly 822 includes LEDs 850 mounted to a PCB 852. The PCB 852is mounted to the chassis 824 via connections 854. For example, the PCB852 includes a tab 856 extending over a ledge 858 of the chassis 824.The connections 854 secure the LED assembly 822 to the ledge 858.Additionally, the connections 854 may be electrical connectionsconfigured to provide power and/or electrical connections to the LEDs850. In certain embodiments, the PCB 852 may include an additional tab856 disposed generally opposite the illustrated tab 856 and configuredto mount to an additional ledge 858 of the chassis 824. However, theadditional tab 856 and the additional ledge 858 are omitted in FIG. 14for purposes of clarity.

The LEDs 850 of the LED assembly 822 are configured to emit lightoutwardly through the fluid flowing between the LED assembly 822 and thecover 826 (e.g., through an upper passage 860 of the cooling system 80)and through the cover 826. In some embodiments, the cover 826 enclosingthe fluid may be acrylic, polycarbonate, glass (e.g., borosilicateglass), or another material having a refractive index between about1.44-1.5. Additionally, the refractive index of the LEDs 850 (e.g., thesilicone), the fluid, and/or the cover 826 may generally be matched(e.g., within a difference threshold).

The cooling system 80 is configured to flow the fluid into the fluidinlet 830, into the upper passage 860 extending between the LED assembly822 and the cover 826 (e.g., as indicated by arrow 862), and into alower passage 864 extending between the LED assembly 822 and the base840 of the chassis 824 (e.g., as indicated by arrow 866). The fluid isconfigured to absorb heat generated by the LED assembly 822 (e.g., dueto operation of the LEDs 850 and the PCB 852 and the light emitted bythe LEDs 850) as the fluid flow through the upper passage 860 and thelower passage 864. Additionally, because the fluid is generallytransparent and/or semi-transparent (e.g., the fluid has a refractiveindex generally between 1.4-1.5), the fluid may have minimal/no effectson the light emitted from the LED assembly 822 and through the fluid. Assuch, the fluid may actively cool the LED assembly 822 during operationof the LED assembly 822 with little to no effect on a quality of lightemitted from the LED assembly 822.

The cooling system 80 is configured to flow the fluid from the upperpassage 860 and into the fluid outlet 834, as indicated by arrow 870,and from the lower passage 864 into the fluid outlet 834, as indicatedby arrow 872. After flowing the fluid over the LED assembly 822 and intothe fluid outlet 834, the pump 108 circulates the fluid through a heatexchanger 106 of the cooling system 80, for example, to cool the fluid.

FIG. 15 is a perspective view of the lighting assembly 820 of FIG. 14,in accordance with one or more current embodiments. As described above,the cooling system 80 is configured to circulate the fluid into thefluid inlet 830 of the chassis 824, over the LED assembly 822 of thelighting assembly 820, and through the fluid outlet 834, thereby coolingthe LED assembly 822. Accordingly, the lighting assembly 820 of FIGS. 14and 15 provides a front emission configuration of a lighting assemblyand LED assembly that may be cooled via the cooling system 80.

FIG. 16 is a flow diagram of a method 900 for controlling the coolingsystem 80 of FIG. 1, in accordance with one or more current embodiments.For example, the method 900, or portions thereof, may be performed bythe controller 120 of the cooling system 80. The method 900 begins atblock 902, where the temperature at an LED assembly (e.g., the LEDassembly 82/196) is measured. The sensor 121 may measure the temperatureand output a signal (e.g., an input signal to the controller 120)indicative of the temperature at or adjacent to the LED assembly (e.g.,a temperature at a surface of the LED assembly, a temperature of thefluid adjacent to and/or flowing over the LED assembly, a temperature ata surface of the enclosure 88/198, etc.). The controller 120 may receivethe signal indicative of the temperature.

At block 904, the temperature at the LED assembly is determined. Block904 may be performed in addition to or in place of block 902. Forexample, block 902 may be omitted from the method 900, and the sensor121 may be omitted from the cooling system 80. The controller 120 may beconfigured to determine the temperature at the LED assembly based onwhether the LED assembly, or portions thereof, are emitting light andbased on an amount of time that the LED assembly, or the portionsthereof, have been emitting light. As generally described above, thecontroller 120 may be configured to control the LED assembly (e.g., bycontrolling which LED arrays 182 are emitting light, a duration that theLED arrays 182 emit light, an intensity of the light emitted by the LEDarrays 182, etc.). Based on the control actions, the controller 120 maydetermine/estimate the temperature at the LED assembly (e.g., thetemperature at the surface of the LED assembly 82/196, the temperatureof the fluid adjacent to and/or flowing over the LED assembly 82/196,the temperature at the surface of the enclosure 88/198, etc.).

At block 906, operating parameter(s) of the cooling system 80 areadjusted based on the temperature at the LED assembly (e.g., thetemperature measured at block 902 and/or determined at block 904). Forexample, the controller 120 may output a signal (e.g., an output signal)to the pump 108 indicative of instructions to adjust the flowrate offluid through the cooling circuit 110. Additionally or alternatively,the controller 120 may output a signal to a heat exchanger (e.g., theheat exchanger 106/601) indicative of instructions to adjust a flow rateof air flowing over a radiator of the heat exchanger (e.g., byoutputting a signal to fans of the heat exchanger 106/601 indicative ofinstructions to adjust a rotational speed of the fans to adjust the flowrate of air). In certain embodiments, the controller 120 may control theLED assembly based on the temperature at the LED assembly, such as byreducing a number of LED arrays emitting light and/or to preventoverheating of the LED assembly.

In certain embodiments, the controller 120 may compare the temperatureat the LED assembly to a target temperature and determine whether adifference between the temperature (e.g., a measured and/or determinedtemperature at the LED assembly 82/196) and the target temperature isgreater than a threshold value. Based on the difference exceeding thethreshold value, the controller 120 may control the operating parametersof the cooling system 80 described above. As such, the controller 120may reduce certain control actions performed by the cooling system 80based on minor temperature fluctuations and/or may reduce an amount ofair flow and/or power used by the heat exchanger to cool the fluid. Thecontroller 120 may receive an input indicative of the target temperature(e.g., from an operator of the cooling system 80) and/or may determinethe target temperature based on a type of LED included in the LEDassembly, a type of fluid circulating through the cooling system 80, amaterial of the enclosure, a material of the tower of the LED assembly,a size of the LED assembly and/or the cooling system 80 generally, or acombination thereof.

After completing block 906, the method 900 returns to block 902 and thenext temperature at the LED assembly is measured. Alternatively, themethod 900 may return to block 904, and the next temperature at the LEDassembly may be determined. As such, blocks 902, 904, and 906 of themethod 900 may be iteratively performed by the controller 120 and/or bythe cooling system 80 generally to facilitate cooling of the LEDassembly and the enclosure.

Debubbler System

FIG. 17 is a cross-sectional view of the debubbler system 112 of FIG. 1,in accordance with one or more current embodiments. As mentioned above,the debubbler system 112 may include a sealed hollow enclosure 950. Thehollow enclosure 950 may include two molded enclosures 952. In certainembodiments, the hollow enclosure 950 may include two left moldedpolycarbonate (PC) enclosures. Furthermore, as illustrated, thedebubbler system 112 may include a debubbler inlet 954 that receivesfluid along the cooling circuit 110 to remove bubbles that build in thefluid as the fluid flows along the cooling circuit 110. The debubblerinlet 954 may include piping of any suitable size for coupling to thecooling circuit 110. For example, the debubbler inlet may include ⅜ inchcross-linked polyethylene (PEX) tubing or piping of any suitablematerial and size. The hollow enclosure 950 may include a first volume(e.g., in a cavity formed at the top of the hollow enclosure 950) havingair and a second volume (e.g., in the bottom portion of the hollowenclosure 950) having the fluid. In certain embodiments, the hollowenclosure 950 may be expandable, such that the hollow enclosure 950 mayexpand as the pressure inside the hollow enclosure 950 increases and/oras the temperature inside the hollow enclosure 950 decreases.

The debubbler system 112 may also include a debubbler outlet 956 thatallows the fluid to exit the debubbler system 112 (to flow to anothercomponent) along the cooling circuit 110. The debubbler outlet 956 mayinclude piping of any suitable size for coupling to the cooling circuit110. In certain embodiments, the debubbler outlet 956 may be of asimilar size as the debubbler inlet 954. In this case, continuing theexample above, the debubbler outlet 956 may include ⅜ inch cross-linkedPEX tubing or piping of any suitable material and size. As illustrated,the debubbler outlet 956 may include an outlet bushing 958 to facilitateexpelling fluid along the cooling circuit 110 via the debubbler outlet956. In certain embodiments, the outlet bushing 958 may be of anysuitable material such as polytetrafluoroethylene (PTFE) or any othersuitable material having a low coefficient of friction. The outletbushing 958 may be right machined.

It should be understood that the position of the debubbler inlet 954 andthe debubbler outlet 956 may be switched. For example, in certainembodiments, the opening defining the debubbler inlet 954 may insteadserve as the debubbler outlet 956 (e.g., to expel fluid out toward thecooling circuit 110), and the opening defining the debubbler outlet 956may instead serve as the debubbler inlet 954 (e.g., to receive fluid viathe cooling circuit 110). In certain embodiments, the distance betweenthe debubbler inlet 954 and outlet 956 may be of any suitable length,such that the fluid surface area exposed to the air is large enough toallow air bubbles in the fluid to rise and join on the surface to escapeto the air inside the hollow enclosure 950. In this manner, the bubbles(e.g., eventually rising to form part of the air inside the hollowenclosure 950) may be exhausted from the hollow enclosure via the checkvalve.

In certain embodiments, the debubbler system 112 may have an innervolume of any suitable size, for example, between about 9 in³ to about70 in³. To facilitate discussion, the example discussed below will be inthe context of a debubbler system 112 having an inner volume of about 35in³. In this example, the fluid level 953 (i.e., the line showing howhigh the fluid fills the hollow enclosure 950 of the debubbler system112) may fluctuate as the fluid expands or compresses due to thefluctuation in temperatures from cooling the LED assembly 82. In thisexample, for a particular type of fluid, the air may occupy 9 in³ andthe fluid may occupy a volume of 26 in³ when the fluid is at a lowesttemperature. Furthermore, in this example, when the fluid is at ahighest temperature, the air may occupy a volume of 15 in³ and the fluidmay occupy a volume of 20 in³. Accordingly, the change in air pressuremay be about 9 in³/15 in³, which may correspond to about a −5.9 poundsper square inch (PSI) change in pressure.

To reduce the increase in pressure resulting from this fluid expansion,the debubbler system 112 may include the check valve 114 that allowsfluid to flow in one direction. In this case, the check valve 114 mayallow gaseous fluid (e.g., air) out of the debubbler system 112, suchthat the check valve 114 prevents any fluids from entering the debubblersystem 112. In this manner, the check valve 114 may allow air to beexpelled from inside of the hollow enclosure 950 of the debubbler system112 when the air inside the hollow enclosure 950 causes the pressureinside the hollow enclosure 950 to rise. As illustrated, the check valve114 may include a corresponding bushing 960 to orient the check valve114 and facilitate the exhaust of gaseous fluid out of the hollowenclosure 950. In certain embodiments, the corresponding bushing 960 maybe of any suitable material such as PTFE or any other suitable materialhaving a low coefficient of friction.

The check valve 114 may be concentric with the corresponding bushing960. An O-ring 962 may facilitate coupling of the bushing 960 to acentral axel 964. In certain embodiments, the central axel 964 may spinin rotational direction 971 about rotation axis 973. In certainembodiments, the central axel 964 may include a u-joint to facilitaterotation about an axis normal to a cross-sectional plane of FIG. 17. Inthis manner, the central axel may rotate about two axes. The check valve114 may be fluidly coupled to a vent tube 966. In certain embodiments,the vent tube 966 may be oriented substantially perpendicular to thecheck valve 114, such that the junction between the check valve 114 andthe vent tube 966 is substantially at a right angle or any degreebetween 45 degrees) (°) and 135°. In certain embodiments, an end 968 ofthe vent tube 966 is positioned opposite the end on which the fluidsits. In this manner, the vent tube 966 may be continuously exposed tothe portion of the debubbler system 112 exposed to the air.

To facilitate this orientation, the debubbler system 112 may include aweighted member 970 positioned opposite the end 968 of the vent tube966. In this manner, gravity may guide the orientation of the debubblersystem 112, such that the preferred positional steady state of thedebubbler system includes an orientation in which the weighted member970 is positioned along the gravity vector. As illustrated, in certainembodiments, the weighted member 970 may surround or abut an internaltubing 972 configured to direct the fluid to the debubbler outlet 956and out of the hollow enclosure 950 toward the cooling circuit 110. Insome embodiments, the weighted member 970 may include a steel blockmachined from 1-inch bar stock and secured to the internal tubing 972 byany suitable fixture (e.g., spring pin). It should be understood thatthe weighted member 970 and the vent tube 966 may be fixed to thecentral axel 964 via any suitable attachment (e.g., pins, weldments, andso forth) opposite the end 968. Furthermore, the central axel 964 mayrotate in rotation direction 971 about rotation axis 973, as discussedin more detail below. As such, rotation of the central axel 964 may alsocause the vent tube 966 and the weighted member 970 to rotate in similardirection. In certain embodiments, the weighted member may be anypercentage of the total weight of the debubbler system 112, such as 25%,50%, 75%, 80% or any suitable percent there between.

FIGS. 18A-18C illustrate respective cross-sectional views of thedebubbler system 112 for a particular orientation. As discussed above,during transportation of the debubbler system 112 and prior toinstallation, the debubbler system 112 may be manipulated to variousorientations. Regardless of the orientation, in some embodiments, airbubbles may be prevented from entering the debubbler system 112, forexample, during transportation. To illustrate one of these orientations,FIG. 18A is a cross-sectional view of the debubbler system 112 of FIG. 1in a first orientation 974 having a weighted member 970 at the bottom ofthe debubbler system 112 of FIG. 1, in accordance with one or morecurrent embodiments. In certain implementations, a portion or theentirety of the weighted member 970 remains below the water level. Inthe first orientation 974, the weighted member 970 may be positioned atthe bottom of the debubbler system 112 relative to a gravity vector 975.As illustrated, when the debubbler system 112 is in the firstorientation 974, the weighted member 970 may align the debubbler inlet954 and the debubbler outlet 956 such that they are under the fluidlevel 953. In this manner, air is prevented from exiting the hollowenclosure 950 during transportation of the debubbler system 112 and/orair cannot enter the debubbler system 112 via the debubbler outlet 956.In certain embodiments, during transportation of the debubbler system112, fluid does not flow through the debubbler inlet 954 and thedebubbler outlet 956. During installation of the debubbler system 112 tothe lighting assembly 70, air bubbles may enter the system (e.g., viathe debubbler inlet or outlet 954, 956). The air bubbles may rise to thetop of the fluid level and settle on the surface (e.g., due to buoyancy)before escaping the fluid and into the air to be removed by the checkvalve 114 (e.g., via the vent tube 966). The distance between thedebubbler inlet 954 and outlet 956 may be of any suitable length, suchthat the fluid surface area exposed to the air is of a size to enableair bubbles in the fluid to rise and join on the surface to escape tothe air inside the hollow enclosure 950.

FIG. 18B is a cross-sectional view of the debubbler system of FIG. 1 ina second orientation 976 having the debubbler inlet 954 orientedopposite a direction of the gravity vector 975, in accordance with oneor more current embodiments. As illustrated, the debubbler system 112may be transported or in operation in the second orientation 976. In thesecond orientation, the fluid level may cover an inlet port 977. Theinlet port 977 may define a conduit out of which the fluid flows afterbeing received at the debubbler inlet 954 from the cooling circuit 110(FIG. 1). In the second orientation, the fluid level may cover the venttube 966, such that the end 968 is under the fluid level 953. In thesecond orientation, the volume of the fluid in the debubbler system 112may be at a fluid level 953 that prevents air from exiting the debubblersystem 112 and/or entering the debubbler system 112 via the debubbleroutlet 956. In certain embodiments, as the fluid compresses or expands(e.g., based on changes in temperature during transportation), air doesnot escape the debubbler system 112. The debubbler system 112 may not bein operation (e.g., receiving and exhausting coolant fluid driven by apump, as discussed below) when it is oriented in the second orientation976, for example, because air bubbles may still leave the fluid, but theair bubbles may not be able to exhaust out of the check valve 114. Thedebubbler system 112 may be oriented in the second orientation 976during transportation of the debubbler system 112.

FIG. 18C is a cross-sectional view of the debubbler system of FIG. 1 ina third orientation 978, in which the debubbler outlet 956 is positionedopposite the gravity vector 975, in accordance with one or more currentembodiments. Similar to in the second orientation 976, in the thirdorientation 978, the fluid level 953 may cover the vent tube 966, suchthat the end 968 is under the fluid level 953. In the third orientation978, the volume of the fluid in the debubbler system 112 may be at afluid level 953 that prevents air from exiting the debubbler system 112and/or enter the debubbler system 112 via the debubbler outlet 956. Incertain embodiments, as the fluid compresses or expands (e.g., based onchanges in temperature during transportation), air does not escape thedebubbler system 112 because the end 968 of the vent tube 966 is underthe fluid level 953. The debubbler system 112 may not be in operation(e.g., receiving and exhausting coolant fluid driven by a pump, asdiscussed below) when it is oriented in the third orientation 978, forexample, because air bubbles may still leave the fluid, but the airbubbles may not be able to exhaust out of the check valve 114. Thedebubbler system 112 may be oriented in the third orientation 978 duringtransportation of the debubbler system 112.

FIG. 19 is a flow diagram of a first arrangement 980 of the coolingsystem 80 of FIG. 1, including the debubbler system 112 of FIG. 17, inaccordance with one or more current embodiments. As described above withrespect to FIG. 3, the cooling system 80 may include an inlet pipe 140fluidly coupled to the pump 108 and to a fluid inlet 142 of the LEDassembly 82. The inlet pipe 140 may direct the flow of fluid into thecenter of the LED assembly 82. The cooling system 80 may also include anoutlet pipe 144 fluidly coupling the outlet 146 to an inlet of the heatexchanger 106 (e.g., radiator 150). The cooling system 80 may include aradiator outlet pipe 982 fluidly coupling the outlet of the heatexchanger to the inlet of the pump 108. The inlet pipe 140, the outletpipe 144, and the radiator outlet pipe 982 are illustrated as a soliddark line to reference that they may collectively define a first coolingflow path 984.

The debubbler system 112 may receive, via debubbler inlet pipe 986, aportion of the fluid directed out from the LED assembly 82. As discussedabove, in certain configuration, the debubbler inlet 954 may serve asthe outlet, while the debubbler outlet 956 may serve as the inlet. Thatis, the outlet pipe 144 may direct fluid to the heat exchanger 106 andthe opening 956 (previously referred to as the debubbler outlet 956).For example, the flow path of fluid exiting the LED assembly 82 maysplit to direct fluid toward the debubbler system 112 and the heatexchanger 106. In certain embodiments, the fluid received by thedebubbler system 112 may bypass the heat exchanger 106 and may expandinside the debubbler system 112 while the check valve 114 removes airbubbles. In certain embodiments, the check valve 114 may releasepressure in response to the pressure within the enclosure exceeding acertain pressure threshold value. For example, for a pump 108 rated tooutput fluid at 3 PSI, the pressure threshold value may be 0.5 PSI, suchthat the check valve 114 may vent air out from the hollow enclosure 950in response to the internal pressure exceeding the pressure threshold(e.g., 0.5 PSI). By venting air out from the hollow enclosure 950 as thepressure rises, the bubbles in the fluid may be reduced, therebyimproving the cooling properties of the fluid and the overall cooling ofthe LED assembly 82.

Fluid received via the opening 956 (previously referred to as thedebubbler outlet 956) may exit the debubbler system 112 via the opening954 (previously referred to as the debubbler inlet 954) by way of adebubbler outlet pipe 988 to join with the radiator outlet pipe 982. Inthis case, the pump 108 may receive fluid from the heat exchanger 106(e.g., via the radiator outlet pipe 982) and from the debubbler system112 (e.g., via the opening 954) to direct the fluid back to the LEDassembly 82. The debubbler system 112 may receive fluid via a secondfluid flow path 990 defined by the outlet pipe 144, the debubbler inletpipe 986, the debubbler outlet pipe 988, and an inlet to the pump 108(as well as all intermediate components, such as the LED assembly 82,the debubbler system 112, and the pump 108). To facilitate illustration,the second fluid flow path 990 is illustrated with a dashed line. Incertain embodiments, the second fluid flow path 990 does not include theheat exchanger 106, such that the debubbler system 112 receives fluidfrom the LED assembly 82 (and not the heat exchanger 106) to remove airbubbles prior to directing fluid back to the pump 108.

FIG. 20 is a flow diagram of a second arrangement 992 of the coolingsystem 80 of FIG. 1, including the debubbler system 112 of FIG. 1, inaccordance with one or more current embodiments. As described above withrespect to FIG. 3, the cooling system 80 may include an inlet pipe 140fluidly coupling the pump 108 to a fluid inlet 142 of the LED assembly82. The inlet pipe 140 may direct the flow of fluid into the LEDassembly 82, as described above with respect to FIG. 8. The coolingsystem 80 may also include an outlet pipe 144 fluidly coupling theoutlet 146 to an inlet of the heat exchanger 106 (e.g., radiator 150),as described above with respect to FIG. 8. The cooling system 80 mayinclude a radiator outlet pipe 982 fluidly coupling the outlet of theheat exchanger to the inlet of the pump 108. The inlet pipe 140, theoutlet pipe 144, and the radiator outlet pipe 982 are illustrated as asolid dark line to reference that they may collective define a firstcooling flow path 984.

As illustrated, the second arrangement 992 includes the debubbler system112. In certain embodiments, the debubbler system 112 may receive fluidfrom two flow paths. First, the debubbler system 112 may receive fluiddirectly from the LED assembly 82, for example, via the fluid outlet 204(e.g., as shown in FIG. 8) by way of the first debubbler inlet pipe986A. Second, the debubbler system 112 may receive fluid from the heatexchanger 106 by way of a second debubbler inlet pipe 986B. For example,the fluid exiting the heat exchanger 106 via the radiator outlet pipe982 may be directed to the pump 108 and the debubbler system 112. Itshould be understood that in certain embodiments, the debubbler system112 may receive fluid from one flow path, such that either the firstdebubbler inlet pipe 986A or the second debubbler inlet pipe 986B may beomitted.

The debubbler system 112 may receive fluid via a second fluid flow path990 defined by the first debubbler inlet pipe 986A, the debubbler outletpipe 988, and an inlet to the pump 108 (as well as all intermediatecomponents, such as the LED assembly 82, the debubbler system 112, andthe pump 108). In certain embodiments, the second fluid flow path 990does not include the heat exchanger 106.

The debubbler system 112 may receive fluid via a third fluid flow path994 defined by the outlet pipe 144, the radiator outlet pipe 982, thesecond debubbler inlet pipe 986B, the debubbler outlet pipe 988, and aninlet to the pump 108 (as well as all intermediate components, such asthe LED assembly 82, the debubbler system 112, and the pump 108, and theheat exchanger 106). In the second arrangement 992, the debubbler system112 receives fluid from the LED assembly 82 and the heat exchanger 106to remove air bubbles that may have developed in the LED assembly 82 andthe heat exchanger 106. Fluid received via the opening 956 (previouslyreferred to as the debubbler outlet 956) may exit the debubbler system112 via the opening 954 (previously referred to as the debubbler inlet954) by way of a debubbler outlet pipe 988 to join with the radiatoroutlet pipe 982. In this case, the pump 108 may receive fluid from theheat exchanger 106 (e.g., via the radiator outlet pipe 982) and from thedebubbler system 112 (e.g., via the opening 954) to direct the fluidback to the LED assembly 82. In an embodiment, the second fluid flowpath 990 and the third fluid flow path 994 may be alternative flowpaths.

In certain embodiments, the fluid received by the debubbler system 112(e.g., from the LED assembly 82 and/or the heat exchanger 106) mayexpand inside the debubbler system 112 and the check valve 114 mayremove air bubbles. In certain embodiments, the check valve 114 mayrelease pressure in response to the pressure within the enclosureexceeding or reaching a certain pressure threshold value. For example,for a pump 108 rated to output fluid at 3 PSI, the pressure thresholdvalue may be 0.5 PSI, such that the check valve 114 may vent air outfrom the hollow enclosure 950 in response to the internal pressureexceeding the pressure threshold (e.g., 0.5 PSI). In this manner, byventing air out from the hollow enclosure 950 as the pressure rises, thebubbles in the fluid may be reduced, thereby improving the coolingproperties of the fluid and the overall cooling of the LED assembly 82.

FIG. 21 is a flow diagram of a third arrangement 996 of the coolingsystem 80 of FIG. 1, including the debubbler system 112 of FIG. 1, inaccordance with one or more current embodiments. While the first andsecond arrangements 980, 992 of FIGS. 19 and 20, respectively, includethe debubbler system 112 as separate from the pump 108, in certainembodiments, the pump 108 may be integral to the debubbler system 112,such that the debubbler system 112 may be positioned in series withrespect to the first cooling flow path 984, as illustrated. In certainembodiments, the debubbler system may be fluidly coupled to the pump 108and/or the heat exchanger 106, for example, in a parallel arrangement.It should be understood that in certain embodiments, such as the thirdarrangement 996, the debubbler system 112 may be fluidly coupled to thepump 108 and the heat exchanger 106, for example, in series.

As described above with respect to FIG. 3, the cooling system 80 mayinclude an inlet pipe 140 fluidly coupling to the pump 108 and to afluid inlet 142 of the LED assembly 82. The inlet pipe 140 may directthe flow of fluid into the center of the LED assembly 82. The coolingsystem 80 may also include an outlet pipe 144 fluidly coupling theoutlet 146 to an inlet of the heat exchanger 106 (e.g., radiator 150).The cooling system 80 may include a radiator outlet pipe 982 fluidlycoupling the outlet of the heat exchanger 106 to the opening 956(previously referred to as the debubbler outlet 956) of the debubblersystem 112.

The debubbler system 112 may receive, via the radiator outlet pipe 982,the fluid from the heat exchanger 106. For example, the fluid exitingthe LED assembly 82 may be directed to the heat exchanger 106 to becooled. Then the fluid may be directed to the debubbler system 112 andthe heat exchanger 106 to remove air bubbles in the fluid. In certainembodiments, the check valve 114 of the debubbler system 112 may releasepressure in response to the pressure within the enclosure exceeding acertain pressure threshold value. For example, for a pump 108 rated tooutput fluid at 3 PSI, the pressure threshold value may be 0.5 PSI, suchthat the check valve 114 may vent air out from the hollow enclosure 950in response to the internal pressure exceeding the pressure threshold(e.g., 0.5 PSI). In this manner, by venting air out from the hollowenclosure 950 as the pressure rises, the bubbles in the fluid may bereduced, thereby improving the cooling properties of the fluid and theoverall cooling of the LED assembly 82. Although FIG. 21 illustrates thedebubbler system 112 and the pump 108 as separate components in series,the debubbler system 112 and the pump 108 may also be combined into asingle component.

FIG. 22 is a rear perspective view of an embodiment of the lightingassembly 187 of FIG. 6A including the cooling system 80 of FIG. 1,having the debubbler system 112 of FIG. 1, in accordance with one ormore current embodiments. To facilitate illustration, the LED assembly82 has been omitted from the schematic diagram of FIG. 22, but the inletpipe 140, the outlet pipe 144, and the valve 156 have been reproduced.As illustrated, the heat exchanger 106 and the pump 108 are mounted tothe chassis 86 of the lighting assembly 70. The heat exchanger 106 mayinclude the radiator 150 and any number of fans 152, as discussed above.

As illustrated, the lighting assembly 187 includes a first bracket 191coupled to the radiator 150 and debubbler system 112, and a secondbracket 195 coupled to the radiator 150 and the pump 108. The first andsecond brackets 191, 195 may include vibration pads. The radiator 150and the debubbler system may be mounted to the first bracket 191, andthe first bracket 191 is mounted to the chassis 86, such that the firstbracket 191 is configured to support a weight of the debubbler system112 and/or at least a portion of a weight of the radiator 150 (e.g., totransfer forces associated with the weight(s) to the chassis 86).Additionally, the radiator 150 and the pump 108 may be mounted to thesecond bracket 195, and the second bracket 195 is mounted to the chassis86, such that the second bracket 195 is configured to support a weightof the pump 108 and/or at least a portion of the weight of the radiator150 (e.g., to transfer forces associated with the weight(s) to thechassis 86). In certain embodiments, the heat exchanger 106, the pump108, and the debubbler system 112 may be housed inside the lightingassembly 187.

FIG. 23 is a perspective view of an inside of the hollow enclosure 950,in accordance with one or more current embodiments. As mentioned above,the hollow enclosure 950 may include two molded enclosures 952 forming asealed cavity. In some embodiments, the hollow enclosure 950 may expand.As illustrated, the vent tube 966 may be positioned on an opposite endfrom the weighted member 970. For example, the vent tube 966 and theweighted member 970 may be fixed to the central axel 964, such that thecentral axel 964 is configured to rotate in rotation direction 971 aboutthe rotation axis 973. The rotation axis 973 may intersect the center ofthe circular cross-section of the central axel 964. The rotation axis973 may be perpendicular to a line formed between the end 968 of thevent tube 966 and the weighted member 970. By rotating relative to therotation axis 973, the vent tube 966 may remain above the fluid levelbecause as the fluid level settles in accordance with the gravity vector975, the weight member 970 may also rotate to settle with the gravity.In addition or alternatively, a u-joint associated with the central axel964 may facilitate rotation along another axis (e.g., perpendicular tothe rotation axis 973).

FIGS. 24, 25, and 26 are respective cross-section views of the debubblersystem 112 of FIG. 2, including a fluid level sensor 115, in accordancewith one or more current embodiments. The fluid level sensor 115 mayinclude photodiode 998 configured to detect light produced by a lightsource 999. The photodiode 998 may include any suitable semiconductordevice configured to convert light into an electrical current (e.g., asignal) communicated to the controller 120 (FIG. 1). The electricalcurrent may be generated in response to photons absorbed by thephotodiode 998. In certain embodiments, the photodiode 998 may includeoptical filters, built-in lenses, and a surface area for receivingphotons.

The light source 999 may include any suitable light source, such as alaser beam (e.g., red laser beam). For example, the light source 999 mayinclude any suitable device that emits light through opticalamplification based on the stimulated emission of electromagneticradiation. The debubbler system 112 may include a mirror 1000 positionedon the central axel 964. In certain embodiments, the mirror 1000 may befixed to the central axel 964, such that the mirror 1000 rotates withthe central axel. The mirror 100 may be disk-shaped with a centralopening such that the internal tubing 972 extends through the centralopening.

As discussed above, the fluid level sensor 115 (e.g., the photodiode 998and the light source 999) may be communicatively coupled to thecontroller 120. The controller 120 may output a signal to the lightsource 999 to cause the light source 999 to emit a light that may bedetected by the photodiode 998. In certain embodiments, the controller120 may be configured to output a signal (e.g., an output signal) to thepump 108 indicative of instructions to adjust the flowrate of the fluidflowing through the cooling circuit 110 based on a fluid level insidethe debubbler system 112. For example, if the fluid level is below afluid level threshold value as determined by the fluid level sensor 115(and communicated to the controller 120), the controller 120 may outputa signal (e.g., an output signal) to the pump 108 indicative ofinstructions to increase the flowrate of the fluid flowing through thecooling circuit 110 to increase the volume within the debubbler system112.

As illustrated in FIG. 24, the fluid level 953 (FIG. 17) may be above athreshold fluid level (e.g., sufficient for fluid to flow through thedebubbler inlet 954 and the debubbler outlet 956). When the fluid level953 is above the threshold fluid level, the light emitted from the lightsource 999 may pass through the fluid. Because the index of refractionassociated with the fluid may be higher than the index of refractionassociated with air, the emitted light may diffract (e.g., bend),reflect off the mirror 1000, and be detected by the photodiode 998. Inthis case, the controller 120 may receive the indication of thedetection of light from the light source 999 by the photodiode 998 tocause the pump 108 to maintain the flow rate of fluid.

As illustrated in FIG. 25, the fluid level 953 (FIG. 17) may be belowthe threshold fluid level. When the fluid level 953 is below a thresholdfluid level (e.g., insufficient for fluid to flow through the debubblerinlet 954 and the debubbler outlet 956), the light emitted from thelight source 999 may pass through air. In this case, the emitted lightmay not be diffracted, so it may go undetected by the photodiode 998(e.g., because the emitted light does not reflect off the mirror 1000toward the photodiode 998). In this case, the controller 120 may receivethe indication of the lack of detection of light from the light source999 by the photodiode 998 to cause the pump 108 to increase the flowrate of fluid.

As illustrated in FIG. 26, the photodiode 998 and light source 999 maybe positioned in close proximity to one another. For example, thephotodiode 998 may be positioned slightly below the threshold fluidlevel and the light source 999 may be positioned above the rotation axis973 and below the photodiode 998. In certain embodiments, the fluidlevel sensor 115 (e.g., the photodiode 998 and light source 999) may bepositioned external to the hollow enclosure 950. In this manner,servicing and replacing the fluid level sensor 115 or any suitablecomponent of the fluid level sensor 115 may be more easily replaced.

FIGS. 27A-C illustrate the lighting assembly 70 and the correspondingdebubbler system 112 in various orientations, in accordance with one ormore current embodiments. In particular, FIG. 27A is a schematic diagramof the lighting assembly 70 of FIG. 1 oriented in an upward position,FIG. 27B is a schematic diagram of the lighting assembly of FIG. 1oriented in a horizontal position, and FIG. 27C is a schematic diagramof the lighting assembly of FIG. 1 oriented in a downward position, inaccordance with one or more current embodiments. To facilitateillustration, FIGS. 27A-C include the coordinate system of FIG. 1 fixedto the lighting assembly and defining a longitudinal axis 90, a lateralaxis 92, and a vertical axis 94. As the lighting assembly 70 is oriented(e.g., to provide light to a particular target) the debubbler system 112may also be oriented, such that the weighted member 970 (and the centralaxel 964) rotates to conform to the gravity vector 975.

Technical effects of the present disclosure include debubbler systemsand methods to reduce bubbles in coolant flow paths associated withlight cooling systems of an electronic systems to improve cooling ofelectronic systems. The debubbler system may include a hollow enclosurethat includes an inlet and an outlet to receive coolant fluid via thecoolant fluid flow path. Technical effects of the present disclosureinclude not allowing air to enter the hollow enclosure duringtransportation of the debubbler system to ensure proper fluid propertiesresultant from reduced air bubbles. The debubbler system may include acheck valve to exhaust air bubbles in the coolant fluid out of thehollow enclosure to reduce air bubbles in the coolant fluid. The checkvalve may be fluidly coupled to the vent tube, such that an opening ofthe vent tube is above the fluid.

This written description uses examples of the presently disclosedembodiments, including the best mode, and also to enable any personskilled in the art to practice the disclosed embodiments, includingmaking and using any devices or systems and performing any incorporatedmethods. The patentable scope of the disclosed embodiments is defined bythe claims, and may include other examples that occur to those skilledin the art. Such other examples are intended to be within the scope ofthe claims if they have structural elements that do not differ from theliteral language of the claims, or if they include equivalent structuralelements with insubstantial differences from the literal language of theclaims. That is, while only certain features of the disclosure have beenillustrated and described herein, many modifications and changes willoccur to those skilled in the art. It is, therefore, to be understoodthat the appended claims are intended to cover all such modificationsand changes as fall within the true spirit of the disclosure.

The techniques presented and claimed herein are referenced and appliedto material objects and concrete examples of a practical nature thatdemonstrably improve the present technical field and, as such, are notabstract, intangible or purely theoretical. Further, if any claimsappended to the end of this specification contain one or more elementsdesignated as “means for [perform]ing [a function]. . . ” or “step for[perform]ing [a function]. . . ”, it is intended that such elements areto be interpreted under 35 U.S.C. 112(f). However, for any claimscontaining elements designated in any other manner, it is intended thatsuch elements are not to be interpreted under 35 U.S.C. 112(f).

The invention claimed is:
 1. A debubbler system, comprising: a hollowenclosure comprising an inlet and an outlet configured to direct flow ofcoolant fluid into and out from the hollow enclosure, respectively; acheck valve configured to exhaust gaseous bubbles in the coolant fluidout of the hollow enclosure to reduce the gaseous bubbles in the coolantfluid; and a vent tube fluidly coupled to the check valve, wherein thevent tube is positioned opposite a weighted member, wherein the weightedmember and the vent tube are fixed to a central axel configured torotate inside the hollow enclosure.
 2. The debubbler system of claim 1,wherein the weighted member is configured to couple to an internaltubing configured to direct the coolant fluid toward the outlet or theinlet.
 3. The debubbler system of claim 1, comprising a fluid levelsensor comprising a photodiode configured to detect a reflected lightfrom a light source and to generate a signal in response to detectingthe reflect light.
 4. The debubbler system of claim 3, wherein thesignal is received by a controller, and wherein the controller isconfigured to send a control signal to a pump to increase, decrease, ormaintain a flow rate of the coolant fluid.
 5. The debubbler system ofclaim 1, wherein a volume of coolant fluid inside the hollow enclosureis maintained during transportation of the debubbler system to preventgas external to the hollow enclosure from entering the hollow enclosure.6. The debubbler system of claim 1, wherein the check valve isconfigured to exhaust the gaseous bubbles in response to an internalpressure inside the hollow enclosure exceeding a threshold pressurevalue, and wherein the threshold pressure value is less than threepounds per square inch (PSI).
 7. The debubbler system of claim 1,wherein the inlet is configured to receive the coolant fluid from anelectronics system.
 8. The debubbler system of claim 1, wherein theinlet is configured to receive the coolant fluid from a light emittingdiode (“LED”) device.
 9. The debubbler system of claim 1, comprising apump fluidly coupled to the outlet of the debubbler system, wherein thepump is configured to drive the flow of the coolant fluid.
 10. Thedebubbler system of claim 1, wherein the inlet is positioned on a firstside of the hollow enclosure and the outlet is positioned on a secondside of the hollow enclosure, wherein the first side is positionedopposite the second side.
 11. A cooling system for a light emittingdiode (“LED”) assembly, comprising: a fluid configured to absorb heatthat is generated by the LED assembly; a heat exchanger configured toremove heat absorbed by the fluid in the LED assembly; an enclosureconfigured to house the LED assembly; a debubbler system configured toreceive the fluid and configured to remove air bubbles from the fluid;and a pump configured to circulate the fluid through the enclosure,through the LED assembly, or both, and through the heat exchanger,wherein the debubbler system and the pump are a single component orseparate components.
 12. The cooling system of claim 11, wherein thedebubbler system comprises: a hollow enclosure comprising an inlet andan outlet configured to direct flow of coolant fluid into and out fromthe hollow enclosure, respectively; a check valve configured to exhaustgaseous bubbles in the coolant fluid out of the hollow enclosure toreduce the gaseous bubbles in the coolant fluid; and a vent tube fluidlycoupled to the check valve, wherein the vent tube is positioned oppositea weighted member, wherein the weighted member is fixed relative to thehollow enclosure.
 13. The cooling system of claim 11, wherein thedebubbler system is configured to receive the fluid directly from theLED assembly directly via a first fluid flow path, wherein the firstfluid flow path fluidly couples a first outlet of the LED assembly to aninlet of the debubbler.
 14. The cooling system of claim 13, wherein thedebubbler system is configured to receive the fluid from an outlet ofthe heat exchanger via a second fluid flow path, wherein the secondfluid flow path couples the outlet of the heat exchanger to the inlet ofthe debubbler.
 15. The cooling system of claim 11, comprising: a fluidlevel sensor comprising a photodiode configured to detect a reflectedlight from a light source and configured to generate a signal inresponse to detecting the reflect light; and a controllercommunicatively coupled to the pump and the fluid level sensor, whereinthe controller is configured to control a flow rate through the pumpbased on the signal.
 16. The cooling system of claim 11, wherein thedebubbler system is configured to receive the fluid only from the heatexchanger and configured to output the fluid only to the pump.
 17. Thecooling system of claim 11, wherein the debubbler system and the pumpare mechanically coupled to a radiator of the heat exchanger by way of arespective bracket member.
 18. A electronics cooling system to reduceair bubbles in an electronics module, the electronics cooling systemcomprising: a pump configured to drive flow of coolant fluid along acooling circuit; and a debubbler system fluidly coupled to the pump viathe cooling circuit, wherein the debubbler system comprises: a checkvalve configured to exhaust gaseous bubbles in the coolant fluid out ofa hollow enclosure to reduce the gaseous bubbles in the coolant fluid;and a vent tube positioned inside the hollow enclosure and fluidlycoupled to the check valve at a first end, wherein the vent tube ispositioned opposite a weighted member, and wherein the vent tube isexposed to air via a second end.
 19. The electronics cooling system ofclaim 18, comprising: an electronic system comprising: an electricalcomponent; and one or more conduits to receive the coolant fluid toremove heat from the electric component.
 20. The electronics coolingsystem of claim 18, wherein a volume of coolant fluid inside the hollowenclosure is maintained above the first end of the vent tube and belowthe second end of the vent tube.